The invention generally relates to a handle for a medical instrument, such as a medical forceps for cutting or grasping tissue in the human or animal body.
The invention more particularly relates to a handle for a medical instrument, comprising a first connecting means for connecting a shaft of said instrument to said handle, said shaft defining a longitudinal axis of said instrument, further comprising a second connecting means for connecting a force transmission element of said instrument to said handle, said second connecting means being movable relative to said first connecting means for moving said force transmission element relative to said shaft for moving at least one tool disposed at the distal end of said shaft, and a first grip element and a second grip element, said first grip element and said second element being movable relative to each other, at least one of said first grip element and said second grip element being operatively connected with said second connecting means.
A handle of the afore-mentioned kind is generally known. Such a handle is generally disposed at the proximal end of the shaft of the instrument and fixed thereto by means of the first connecting means. The tool or the tools of the instrument are disposed at the distal end of the shaft.
In use of the instrument in surgery the surgeon holds the instrument in hand by gripping the two grip elements of the handle. The grip elements further have the function as actuating or operating elements for moving the tools at the distal end of the shaft. To this end the grip elements are movable relative to each other, i.e. at least one of the two grip elements is movable and the other one is immovable or stationary, or both the grip elements are movable.
At least the movable grip element is operatively connected to the second connecting means, in order to transfer a hand force applied to the movable grip element to the force transmission element and by means of the latter to the movable tool.
The most widely used type of handles comprises grip elements, which are configured in a scissors-like fashion. Such a scissors-like handle is, for example, disclosed in U.S. Pat. No. 5,810,883. The grip elements of this known handle both are configured in form of legs extending laterally at substantially right angles from the longitudinal axis of the shaft.
The two legs of the grip elements of this known handle are disposed longitudinal by one behind the other in the same plane and are movable relative to each other in that the distal leg is hinged-mounted to the proximal immovable leg. At their free ends the two legs each comprise a ring each, the ring of the proximal leg being intended for passing through the thumb and the ring of the distal leg for passing through the index or the middle finger or both.
In use in a surgical operation, this afore-mentioned handle is usually held in a position, where the legs of the grip elements stand about up-right. In this position of the handle the surgeon's hand is most relaxed, since the wrist of the hand is straight and not bent.
However, when performing a surgical operation it is often necessary to rotate the whole instrument about its longitudinal axis in order to bring the tool or tools, e.g. the jaw parts in another position at the surgical site or to a surgical site which is difficult to be accessed. Since the tool or the tools are fixed to the shaft and to the force transmission element, it is necessary in order to rotate the tools to rotate the whole instrument including the handle about the longitudinal axis of the instrument. In case of the afore-mentioned known handle this means that for rotating the instrument the legs of the grip elements must be brought into an inclined, horizontal or even a reversed up-right position.
In order to bring the instrument in such a rotated position the surgeon, therefore, must twist the wrist of his hand. Holding and simultaneously operating the grip elements in such a rotated position with a twisted or bent wrist is very difficult and cumbersome, and the surgeon's hand faster fatigues or even suffers a cramp.
The known handle, therefore, has the disadvantage that it is not sufficiently comfortable and not sufficiently ergonomic for all situations of use which may occur in surgical applications of the instrument the handle is connected to.
It is, therefore, an object of the present invention to provide a handle, which is more ergonomic and more comfortable in use, and which contributes to delaying the occurance of fatigue when working with the instrument in a wide range of working positions.